1. Field of the Invention
This invention relates to certain alkaline earth metal salts of vicinally hydroxy, alkoxy-substituted C.sub.16 -C.sub.22 fatty acids, to a process for their preparation, and to their use as catalysts for the ethoxylation or propoxylation of compounds containing active hydrogen atoms.
2. Statement of Related Art:
Fatty alcohol ethoxylate and propoxylates are widely used as nonionic detergents. They are prepared by reaction of fatty alcohols normally containing from 10 to 18 carbon atoms with ethylene oxide or propylene oxide in the presence of catalysts, the fatty alcohols reacting with several molecules of ethylene oxide or propylene oxide.
The following catalysts inter alia have been used for the above-mentioned polyalkoxylation reaction:
calcium and strontium hydroxides, alkoxides and phenoxides (U.S. Pat. No. 4,453,022), PA0 calcium alkoxides (U.S. Pat. No. 4,396,779), PA0 barium hydroxide (EP-B 01 15 083), PA0 basic magnesium compounds, for example alkoxides (EP-A- 00 82 569), PA0 magnesium and calcium fatty acid salts (EP-A 0 85 167). PA0 low pour points PA0 relatively high smoke points PA0 fewer moles of alkoxide needed to acquire solubility in water PA0 fewer hydrotropes for introduction into heavy duty liquid detergents PA0 a fainter odor attributable to the presence of free (unreacted) fatty alcohols, PA0 less pluming during spray drying.
Other known polyalkoxylation catalysts are potassium hydroxide and sodium methylate.
The catalysts set forth above are attended inter alia by the disadvantage that they are difficult to incorporate in the reaction system and/or are difficult to produce.
A narrow range of the degree of polyalkoxylation is of particular importance to fatty alcohol polyalkoxylates, cf. JAOCS, Vol., 63, 691-695 (1986), and HAPPI, 52-54 (1986). Accordingly, so-called "narrow-range" alkoxylate have the following advantages in particular:
The range of homolog distribution of fatty alcohol polyalkoxylates is essentially determined by the type of catalyst used. A measure of the homolog distribution is the so-called Q-value according to the following equation: EQU Q=n p.sup.2
in which n is the average adduct number (mean degree of ethoxylation) and p is the percentage of adduct having a certain EO degree which is predominantly formed. Accordingly, a high Q value signifies a narrow homolog distribution range.